[Drakelist] TR-7A Shutting Down At High Power
I have a friend who remarked that his TR-7A shuts down when he tries to run full rf output. Otherwise the rig runs fine. Is this problem related to the current adjust pot in the PS-7 power supply? Any suggestions would be appreciated Tnx 73 Ed K2ZE ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR-7A Shutting Down At High Power
Ed, From my limited experience, that is indeed the problem, the PS-7 is current limiting due to a need to adjust it. I think that instructions for adjustment are in the PS-7 manual. One friend's rig had a bad pass transistor and exhibited this same symptom, however. I would still try the adjustment first. 73, Don, WB5HAK___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR-7A Shutting Down At High Power
As a side note, full power means different things to different people. If the final brick is adjusted for max output, then yes more current will be drawn but so also the instability might rear its ugly head. Best to keep things at a manageable level... -Original Message- From: rfch...@verizon.net To: drakelist@zerobeat.net Sent: Wed, Apr 13, 2011 2:24 pm Subject: [Drakelist] TR-7A Shutting Down At High Power I have a friend who remarked that his TR-7A shuts down when he tries to run full rf output. Otherwise the rig runs fine. Is this problem related to the current adjust pot in the PS-7 power supply? Any suggestions would be appreciated Tnx 73EdK2ZE ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR-7A Shutting Down At High Power
Also have your friend check his grounding. Stray RF getting into the PS-7 will also shut it down. 73 Lee WB6SSW ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR-7A Shutting Down At High Power
Lee is very correct about the PS7 and a little bit of stray RF. If you have any accessories on the 12 volt line (RCA jack) of the PS7, make sure that there is a .01uf cap across that line inside the PS7. I believe that was a factory upgrade/mod fairly early in the PS7 history. Usually this show most often on 40 meters becasue it is the peak gain of the original final RF brick. If you fix it there, you then usually have a stable PS7. BTW if you are not currently using a switched AC power socket, I would recommend that you look into one (computer switch deck is a good solution). The TR7 power switch/pot combo is put under quite a bit of stress with on/off cycles. I have not tried to locate a duel pot, duel switch combo, but my guess is that it is non-existent. 73, Ron WD8SBB --- On Wed, 4/13/11, leecra...@aol.com leecra...@aol.com wrote: From: leecra...@aol.com leecra...@aol.com Subject: Re: [Drakelist] TR-7A Shutting Down At High Power To: rfch...@verizon.net, drakelist@zerobeat.net Date: Wednesday, April 13, 2011, 4:16 PM Also have your friend check his grounding. Stray RF getting into the PS-7 will also shut it down. 73 Lee WB6SSW -Inline Attachment Follows- ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
